I’m Uttoxeter way, JR Classics in Doncaster get decent reviews but they are over an hour away for me. You’re probably going to have to travel to Greater Manchester or the West Midlands for a decent four figure job.
I think an MX5OC discount used to be available but it was a few years ago. The best thing IMHO would be for you to chat to two or three places and find out what approach they would take and how far they will go, then pick the option your wallet and head are comfortable with. I say this because I’ve seen everything discussed from simply covering up the problem for a low price through to stripping absolutely everything back to bare metal, using more than one product, taking many days, and producing a collection of photos of the work.